U.S. intelligence agencies say they believe Pakistani Taliban leader Hakimullah Mehsud died in a firefight with a rival faction weeks ago.
U.S. authorities are in the process of reviewing their information before they can definitively say Hakimullah Mehsud is dead.
So far, there has not been any evidence to confirm Mehsud's death.
But the recent U.S. comments confirm what Pakistani officials said weeks ago, that they believe Mehsud died during Taliban infighting following the death of former group leader Baitullah Mehsud.
Officials believe a U.S. missile strike killed Baitullah Mehsud in early August while he was at his father-in-law's compound in South Waziristan. Earlier this week, the British Broadcasting Corporation's Urdu-language service aired video allegedly showing Mehsud's body.
Hakimullah Mehsud supposedly called news outlets after rumors of his death first arose, but Pakistani officials say they have reason to believe that it was Mehsud's cousin pretending to be the Taliban leader.
Also on Friday, Pakistani intelligence officials said they believed a U.S. missile strike in South Waziristan in late August killed Tahir Yuldashev, an Uzbek militant leader with links to al-Qaida. The Taliban immediately denied the report.
If both Mehsuds and Yuldashev have indeed died, then security analyst Khalid Aziz says the militants should be scrambling for new leaders.
But he cautions that the military would still face a strong fight in the area.
"The militants have the telephones [and] the wireless communication," he said. "They are well-armed. They are well-organized. And so they balance out the advantages to a large extent that the state has."
Meanwhile, the Pakistani army has blocked all entry and exit routes out of South Waziristan, where officials believe Mehsud's fighters are based.
While the military has not publicly set a date for any major operation in the area, U.N. officials say some 80,000 civilians have fled the region in anticipation of a new offensive.